<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>copyWithin</title>
</head>

<body>
  <script>
    let a = [1, 2, 3, 4, 5];
    console.log(a.copyWithin(1));
    console.log(a.copyWithin(2, 3, 5));
    // console.log(a.copyWithin(0, -3, -1));

  </script>
</body>

</html>